PROBE OF THE INTERACTION BETWEEN DARK SECTORS ON THE LARGE SCALE COSMIC MICROWAVE BACKGROUND ANISOTROPIES

2011 ◽  
Vol 20 (10) ◽  
pp. 2121-2124
Author(s):  
JIAN-HUA HE ◽  
BIN WANG
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Significant Influence ◽  
Large Scale ◽  
Power Spectra ◽  
Data Sets ◽  
Late Time ◽  
Microwave Background ◽  
Coincidence Problem

In this review, we study the signature of the interaction between dark energy (DE) and dark matter (DM) on the large-scale CMB anisotropies. We find the interaction has significant influence on the late time Integrated Sachs Wolfe effect (ISW). The positive coupling could suppress the low-l part of the power spectra. We also confront the interacting models with WMAP 5-year as well as other data sets. We find that these models are well-fitted and in 1σ range, the constrained coupling between dark sectors can solve the coincidence problem.

scholarly journals COSMOLOGY WITH MIRROR DARK MATTER II: COSMIC MICROWAVE BACKGROUND AND LARGE SCALE STRUCTURE

2005 ◽  
Vol 14 (02) ◽  
pp. 223-256 ◽  
Author(s):  
PAOLO CIARCELLUTI
Keyword(s):  
Dark Matter ◽  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Large Scale ◽  
Cosmological Parameters ◽  
Power Spectra ◽  
Linear Regime ◽  
Microwave Background ◽  
Primordial Nucleosynthesis ◽  
Standard Cosmology

This is the second paper of a series devoted to the study of the cosmological implications of the existence of mirror dark matter. The parallel hidden mirror world has the same microphysics as the observable one and couples the latter only gravitationally. The primordial nucleosynthesis bounds demand that the mirror sector should have a smaller temperature T′ than the ordinary one T, and by this reason its evolution can be substantially deviated from the standard cosmology. In this paper we take scalar adiabatic perturbations as the input in a flat Universe, and compute the power spectra for ordinary and mirror CMB and LSS, changing the cosmological parameters, and always comparing with the CDM case. We find differences in both the CMB and LSS power spectra, and we demonstrate that the LSS spectrum is particularly sensitive to the mirror parameters, due to the presence of both the oscillatory features of mirror baryons and the collisional mirror Silk damping. For x<0.3 the mirror baryon–photon decoupling happens before the matter–radiation equality, so that CMB and LSS power spectra in linear regime are equivalent for mirror and CDM cases. For higher x-values the LSS spectra strongly depend on the amount of mirror baryons. Finally, qualitatively comparing with the present observational limits on the CMB and LSS spectra, we show that for x<0.3 the entire dark matter could be made of mirror baryons, while in the case x≳0.3 the pattern of the LSS power spectrum excludes the possibility of dark matter consisting entirely of mirror baryons, but they could present as admixture (up to ~50%) to the conventional CDM.

The cosmic microwave background: from discovery to precision cosmology

2019 ◽  
pp. 291-345
Author(s):  
R. Bruce Partridge
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Power Spectra ◽  
Expansion Rate ◽  
Microwave Background ◽  
The Universe ◽  
Cosmic Origin ◽  
Precision Cosmology

Observations of the cosmic microwave background (CMB) form the basis for modern ‘precision cosmology’. This chapter treats the discovery of a ≈3 K microwave background and the demonstration of its cosmic origin. Key observational results, up to and including the results from the COBE mission, follow. The major impact of the CMB comes from measurements of the power spectra of fluctuations in the temperature and polarization. The chapter ends with results derived from the power spectra obtained by the Planck mission, including values for the baryon, dark matter, and dark energy densities; the curvature of space; and the expansion rate of the Universe.

scholarly journals Cosmology from large-scale structure

2020 ◽  
Vol 633 ◽  
pp. L10 ◽  
Author(s):  
Tilman Tröster ◽  
Ariel. G. Sánchez ◽  
Marika Asgari ◽  
Chris Blake ◽  
Martín Crocce ◽  
...  
Keyword(s):  
Cosmic Microwave Background ◽  
Parameter Space ◽  
Large Scale ◽  
Bayes Factor ◽  
Large Scale Structure ◽  
Data Sets ◽  
Microwave Background ◽  
Shape Information ◽  
Galaxy Clustering ◽  
Cosmological Constraints

We reanalyse the anisotropic galaxy clustering measurement from the Baryon Oscillation Spectroscopic Survey (BOSS), demonstrating that using the full shape information provides cosmological constraints that are comparable to other low-redshift probes. We find Ωm = 0.317+0.015−0.019, σ8 = 0.710±0.049, and h = 0.704 ± 0.024 for flat ΛCDM cosmologies using uninformative priors on Ωch2, 100θMC, ln1010As, and ns, and a prior on Ωbh2 that is much wider than current constraints. We quantify the agreement between the Planck 2018 constraints from the cosmic microwave background and BOSS, finding the two data sets to be consistent within a flat ΛCDM cosmology using the Bayes factor as well as the prior-insensitive suspiciousness statistic. Combining two low-redshift probes, we jointly analyse the clustering of BOSS galaxies with weak lensing measurements from the Kilo-Degree Survey (KV450). The combination of BOSS and KV450 improves the measurement by up to 45%, constraining σ8 = 0.702 ± 0.029 and S8 = σ8 Ωm/0.3 = 0.728 ± 0.026. Over the full 5D parameter space, the odds in favour of a single cosmology describing galaxy clustering, lensing, and the cosmic microwave background are 7 ± 2. The suspiciousness statistic signals a 2.1 ± 0.3σ tension between the combined low-redshift probes and measurements from the cosmic microwave background.

scholarly journals Constraints on neutrino-dark matter interactions from cosmic microwave background and large scale structure data

2010 ◽  
Vol 81 (4) ◽  
Author(s):  
Paolo Serra ◽  
Federico Zalamea ◽  
Asantha Cooray ◽  
Gianpiero Mangano ◽  
Alessandro Melchiorri
Keyword(s):  
Dark Matter ◽  
Cosmic Microwave Background ◽  
Structure Data ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Microwave Background

Cosmology Today

Daedalus ◽  
2014 ◽  
Vol 143 (4) ◽  
pp. 125-133
Author(s):  
David N. Spergel
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Gravitational Lensing ◽  
Large Scale ◽  
Empty Space ◽  
Microwave Background ◽  
Astronomical Observations ◽  
Basic Parameters ◽  
Age Of The Universe ◽  
The Universe

We seem to live in a simple but strange universe. Our basic cosmological model fits a host of astronomical observations with only five basic parameters: the age of the universe, the density of atoms, the density of matter, the initial “lumpiness” of the universe, and a parameter that describes whether this lumpiness is more pronounced on smaller physical scales. Our observations of the cosmic microwave background fluctuations determine these parameters with uncertainties of only 1 to 2 percent. The same model also provides an excellent fit to the large-scale clustering of galaxies and gas, the properties of galaxy clusters, observations of gravitational lensing, and supernova-based measurements of the Hubble relation. This model implies that we live in a strange universe: atoms make up only 4 percent of the visible universe, dark matter makes up 24 percent, and dark energy – energy associated with empty space – makes up 72 percent.

scholarly journals Void asymmetries in the cosmic web: a mechanism for bulk flows

2014 ◽  
Vol 11 (S308) ◽  
pp. 561-570
Author(s):  
J. Bland-Hawthorn ◽  
S. Sharma
Keyword(s):  
Dark Matter ◽  
Cosmic Microwave Background ◽  
Large Scale ◽  
Local Group ◽  
3D Structure ◽  
Moving Frame ◽  
Microwave Background ◽  
Local Universe ◽  
Scale Separation

AbstractBulk flows of galaxies moving with respect to the cosmic microwave background are well established observationally and seen in the most recent ΛCDM simulations. With the aid of an idealised Gadget-2 simulation, we show that void asymmetries in the cosmic web can exacerbate local bulk flows of galaxies. The {\it Cosmicflows-2} survey, which has mapped in detail the 3D structure of the Local Universe, reveals that the Local Group resides in a “local sheet” of galaxies that borders a “local void” with a diameter of about 40 Mpc. The void is emptying out at a rate of 16 km s-1Mpc-1. In a co-moving frame, the Local Sheet is found to be moving away from the Local Void at ∼ 260 km s-1. Our model shows how asymmetric collapse due to unbalanced voids on either side of a developing sheet or wall can lead to a systematic movement of the sheet. We conjectured that asymmetries could lead to a large-scale separation of dark matter and baryons, thereby driving a dependence of galaxy properties with environment, but we do {\it not} find any evidence for this effect.

scholarly journals A fake interacting dark energy detection?

2020 ◽  
Vol 500 (1) ◽  
pp. L22-L26
Author(s):  
Eleonora Di Valentino ◽  
Olga Mena
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Hubble Constant ◽  
Energy Detection ◽  
Microwave Background ◽  
Planck Data ◽  
Cosmological Constraints ◽  
Data Analyses ◽  
Constant Tension

ABSTRACT Models involving an interaction between the dark matter and the dark energy sectors have been proposed to alleviate the long-standing Hubble constant tension. In this paper, we analyse whether the constraints and potential hints obtained for these interacting models remain unchanged when using simulated Planck data. Interestingly, our simulations indicate that a dangerous fake detection for a non-zero interaction among the dark matter and the dark energy fluids could arise when dealing with current cosmic microwave background (CMB) Planck measurements alone. The very same hypothesis is tested against future CMB observations, finding that only cosmic variance limited polarization experiments, such as PICO or PRISM, could be able to break the existing parameter degeneracies and provide reliable cosmological constraints. This paper underlines the extreme importance of confronting the results arising from data analyses with those obtained with simulations when extracting cosmological limits within exotic cosmological scenarios.

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